diff --git a/libc/include/llvm-libc-macros/unistd-macros.h b/libc/include/llvm-libc-macros/unistd-macros.h
index 4f27f075fcc61..e09dada04a19d 100644
--- a/libc/include/llvm-libc-macros/unistd-macros.h
+++ b/libc/include/llvm-libc-macros/unistd-macros.h
@@ -5,4 +5,8 @@
 #include "linux/unistd-macros.h"
 #endif
 
+#define STDIN_FILENO 0
+#define STDOUT_FILENO 1
+#define STDERR_FILENO 2
+
 #endif // LLVM_LIBC_MACROS_UNISTD_MACROS_H